@Phijkchu_Pikachu:
d4! - 1 = (1) - 1 = 0
d4! - 1 = (1) - 1 = 0d20! /2 = (9) /2 = 4.5d4! /2 = (3) /2 = 1.5d20!%17 = (1)%17 = 1d20!%15 = (4)%15 = 4d4!%15 = (2)%15 = 2d2!%15 = (2+2+1)%15 = 5d5!%15 = (2)%15 = 2d2!%15 = (2+1)%15 = 3d3!%15 = (1)%15 = 1d1488 = (732) = 732d1488 = (1218) = 1218d1488 = (711) = 711d2020 = (1954) = 1954d1488 = (1365) = 1365d1488 = (686) = 686d7777 = (5277) = 5277d20! = (20+6) = 26d26! = (14) = 14d14! = (8) = 8d8! = (4) = 4d4! = (1) = 1d7777 = (7632) = 7632d2020 = (1081) = 1081d1488 = (664) = 6642d6 = (3+1) = 4